Under certain circumstances, railroads are one of the more energy efficient methods of transporting both passengers and freight. There has been a movement toward railed mass transit systems in many large cities for many reasons, including the conservation of petroleum consumed by automobiles of commuters and the emissions and traffic problems resulting from large numbers of low occupancy vehicles. While such railed mass transit systems have been proposed in many cities, the costs of right of way acquisition, construction of the railroad itself and passenger stations, the cost of purchasing rolling stock, and the like are all very high. While mass transit systems would save riders the costs of operating their automobiles for commuting and would, to some extent, reduce the cost of street maintenance, funds for construction of new railed systems and extensions and maintenance of existing systems are often difficult to obtain.
Even with the best conventional machinery available, the construction of railroads, like many other types of construction, is labor intensive. Thus, any tool or method which can increase the productivity of railroad construction workers, without compromising their safety or the quality of their work, is desirable from an economic standpoint. Additionally, anything which can increase the useful life of a railroad and its structural components is economically desirable Most existing railroads in this country are constructed using wooden cross ties positioned on a track bed of crushed rock. The rails are secured to the ties by large spikes. Since conventional wooden ties usually weigh in the neighborhood of a hundred pounds, they are usually hefted into place on the track bed manually. Such work is arduous, and injuries to workers performing such labor are not uncommon. Additionally, construction process is slow.
While the use of wooden railroad cross ties has many advantages, it also has disadvantages. Wooden ties are chemically treated to resist deterioration; however, such treatments do not extend to great depths within the ties. The effects of weathering and load bearing can cause cracks in the ties which expose untreated portions of the ties to additional weathering and destructive insects and molds. Regular inspection, maintenance procedures, and, often, replacement of wooden ties is required to avoid possible rail accidents caused by the deterioration of the ties.
In an effort to extend the life of railroad structural components and lessen maintenance costs, reinforced concrete cross ties have been developed and are being used in some new railroad construction. Although not entirely immune to some long term weathering effects, concrete ties are not susceptible to insect and mold deterioration and, thus, are projected to have significantly longer useful lives. One problem with concrete ties is that they weight considerably more than wooden ties, ranging from about six to eight hundred pounds per tie depending on the rail gauge and expected load capacity. At such a weight, lifting machinery is required for coarse positioning of the concrete ties, with final alignment and spacing performed using hand tools. Even with such machinery, little saving in labor has been realizable, and construction progress may actually be slower with concrete ties than with wooden ties. Additionally, the great weight of concrete ties increases the severity of hazards to workers handling such ties. The economic advantage of longevity of concrete over wooden ties is offset to some extent by higher costs in the manufacture and installation of concrete ties.